Winch

ABSTRACT

A multiple-speed winch having a plurality of independently rotatable pinions coaxial with a drive shaft, drive linkages of varying mechanical advantage connecting these pinions to the winch drum and a shaft engager for engaging a selected pinion to the drive shaft. The shaft engager includes drive cams associated with the pinions and mounted for movement between an extended position which prevents relative rotation of pinion and shaft and a retracted position which permits rotation; selective extension of the drive cams causes the shaft to drive selected pinions.

United States Patent Carter [4 June 20, 1972 41 WINCH [$6] nae-mm cm[72] Inventor: John Henry Carter, Lincoln, Mass. UNITED TATE PATENTS 73Assignee; Ammmne Corporation Weston, Mass 3,145,974 8/ l964 Short..254/l50 R [22] Filed: May 5, 1971 Pn'mary Examiner-Leonard H. Gerin[2]] pp No: 140,332 Attorney-Martin Klrkpartnck Related us. Applicationum [57] ABSTRACT A multiple-speed winch having a plurality ofindependently Dlvlslon of Se". NO. Feb. 7, Pat. NO. rotatable pinionscoaxial a d ive hah d i e linkag of varying mechanical advantageconnecting these pinions to the winch drum and a shah engager forengaging a selected pinion US. Cl. 74/325, 3.54, R to the drive shaft.The engage includes drive cams as. [51 Int. Cl ..Fl6h 3/08, Fl 6d 67/00,866d 1/30 sociated with the pinions and mounted for movement between[58] Field of Search ..254/150 R; 74/325; 192/351, an extended positionwhich prevents relative rotation of pinion and shaft and a retractedposition which permits rotation; selective extension of the drive camscauses the shaft to drive selected pinions.

3Clailm,7DrawingFigum PATENTEDaunzo m2 SHEET 2 [If 3 WINCH Thisinvention is a division of Ser. No. 799,802, filed Feb. 17, 1969, now U.S. Pat. No. 3,599,937, and relates to a multiple-speed winch.

The primary object of the invention is to provide a winch having aselection of power ratios and provision for changing from one ratio toanother rapidly and conveniently even when the winch drum is under load.Another object of the invention is to provide such a winch which, withrespect to its hauling capacity and mechanical strength is solightweight and compact as to be excellently suited for use aboardhigh-performance sail boats.

The invention features a shaft engaged for transmitting rotary motion ofa drive shaft to any of a plurality of independently rotatable pinionscoaxial with the shaft, the shaft engaged including a plurality of drivecams each associated with a given pinion and mounted to the shaft formovement from a first extended position engaging the associated pinionand preventing relative rotation between the pinion and the shaft (in atleast one direction) to a second retracted position permitting relativerotation, and means for selectively extending the drive cams and thusengaging the drive shaft to selected pinions.

In preferred embodiments, each pinion is associated with a drive linkageconnecting it to an independently rotatable winch drum, the drivelinkages being of varying mechanical advantage. The choice of theparticular drive cams that are extended is controlled by the angularorientation of a rotatable cam-control rod within the drive shaft andcoaxial with it. The drive shaft is freely rotatable in the reversedirection with respect to all the pinions (permitting the shaft to becranked backwards without moving the winch drum, and also permitting thewinch drum to be pulled through in the forward direction (e.g. bymanually hauling in a line wrapped around the winch drum withoutrotating the drive shaft or crank). Three pinions are employed, a first(high-speed) pinion directly connected to the winch drum, a secondmediumspeed pinion connected to the winch drum through a stepdown drivelinkage, and a third low-speed pinion connected to the drum throughanother step-down drive linkage having a greater step-down ratio. Thewinch drum is positively prevented from rotating in a backward directionby a basemounted pawl mechanism. The winch drum is forwardly rotatablewith respect to the low-speed linkage, providing isolation of thatlinkage from the drum. For strength and lightness the body of the winchdrum is made of cast nylon.

Other objects, features, and advantages will appear from the followingdescription of a preferred embodiment of the invention taken togetherwith the attached drawings thereof, in which:

FIG. 1 is a perspective view of the entire winch;

FIG. 2 is an exploded isometric view of the drive shaft and shaftengager;

FIG. 3 shows diagrammatically the base, drive linkages, and portions ofthe drive shaft;

FIG. 4 is a sectional view taken on line 4-4 of FIG. 1.

FIG. 5 is a sectional view of the pawl mechanism used to prevent reverserotation of the winch drum taken on line 5-5 of FIG. 3;

FIG. 6 is a sectional view of the drive shaft, drive cams, cam-controlrod, and high-speed pinion taken on line 6-6 of FIG. 3 with the pinionengaged to the drive shaft;

FIG. 7 is a similar view but with the cam-control rod rotated so thatthe high-speed pinion is disengaged from the drive shaft.

There is shown in FIG. 1 the winch drum 22 rotatably mounted to fixedbase 24, the drive shaft 26 concentric with the drum and also rotatablewith respect to base 24, crank 28 secured to the upper end of the driveshaft and provided with a handle 30. A similar crank (not shown) can besecured to the lower end of the drive shaft instead of (or in additionto) theupper crank (thus permitting below-deck operation of the winch ortwo-handed operation).

Concentric with drive shaft 26 is high-speed pinion" 32. (As usedherein, pinion" is not intended to be limited to gears alone, butincludes any comparable member driven by a rotating coaxial shaft. Inthe preferred embodiment, highspeed pinion 32 is directly keyed to thewinch drum 2 butit may, in other embodiments, be integral with thedrum.) Also concentric with drive shaft 26 are medium-speed pinion 34connected to the drum through a step-down drive linkage (not shown), andlow-speed pinion 36 also connected to the drum through another step-downdrive linkage (not shown). When high-speed pinion 32 is engaged to shaft26, each full rotation of crank 28 causes a full rotation of drum 22with respect to base 24; when medium-speed pinion 34 is engaged to theshaft, 4.25 full rotations of crank 28 are required to produce a fullrotation of the drum; when low-speedpinion 36 is engaged to the shaft,11.05 full'rotations of crank 28 are required to produce a full rotationof the drum.-In the preferred embodiment, the ratio of crank radius todrum radius is about 4.5 to l. Consequently, the winch provides powerratios (mechanical advantages) of about 4.5, 19, and 50.

Referring to FIG. 2,'the shaft 26 is keyed to crank-nut 40 by the pins42 cooperating with split-bores 43 and is further secured by retainingnut 44. Attachment of crank 28 to cranknut 40 thus holds shaft 26 andcrank 28 fixed withrespect to each other. Shaft 26 contains three setsof opposed drive-cam recesses 52, 54, and 56, the two recesses of eachset being 180 apart on the drive shaft and the three sets of recessesbeing axially aligned. Drive earns 62 with associated spring elements62a are mounted in drive-cam recesses 52 to permit the engagement ofshafi26 to high-speed pinion 32. Similar drive cams and spring elements(not shown) are mounted on drive-cam recesses 54 to permit engagement ofmedium-speed pinion 34, and in drive-cam recesses 56 to permitengagement of low-speed pinion 36. Spacer 35 fixes the axial separationbetween pinions 34 and 36 and facilitates their rotation.

Cam-control rod is inserted in axial bore 71 of drive shaft 26 and isrotatable within the drive shaft by means of control knob 73 secured toits upper end. The cam-control rod is provided with three sets ofopposed cam-control grooves 72, 74, and 76, the two grooves of each setbeing apart on the cam-control rod and the three sets of grooves beingspaced 60 apart. When the cam-control rod is rotated so that grooves 72register with earns 62, the cams are extended by spring elements 620 (asshown in FIG. 6) and high-speed pinion 32 is rotatably engaged to shaft26. The earns 62 transmit forward (clockwise) rotation of the driveshaft 26 to internal teeth 33 of high-speed pinion 32, and keys 32asecure the pinion to winch drum 22 so that the drum rotates with driveshaft'26 when crank 28 is forward rotated.

When cam control rod 70 is rotated in additional 60 camcontrol grooves74-register with the corresponding pair of drive cams, causing the camsto be extended and engaging medium-speed pinion 34 to drive shaft 26.Because cams 62 no longer register with grooves 72, spring elements 62acan no longer extend the cams, and high-speed. pinion 32 is disengagedfrom the drive shaft (as shown in FIG. 7). Mediumspeed pinion 34, whenengaged to shaft 26, drives winch drum 22 through the medium-speed drivelinkage, the step-down gear train between pinion 34 and internal ringgear 23 secured within drum 22 (see FIGS. 3 and 4).

A further 60 rotation of cam-control rod 70 causes camcontrol grooves 76to register with the corresponding pair of drive cams and extension ofthese cams engages low-speed pinion 36 to drive shaft 26. Bothhigh-speed pinion 32 and medium-speed pinion 34 are then disengaged fromthe drive control knob 73 (see FIG. 4) to ensure correct angularregistration of the selected pair of drive cams with the correspondingcam-control grooves on cam-control rod 70. Control knob 73 can bemanually rotated to select the desired mechanical advantage even whenthe winch drum is under load, provided that no forward torque is appliedto crank 28 while changing speeds. (Because of the pawl mechanismpreviously referred to, backward rotation of the loaded drum isprevented when application of torque to the drum is interrupted.)

FIG. 3 is a diagrammatic representation'of the base, drive linkages, andportions of the drive shaft. Medium-speed pinion 34, when engaged todrive shaft 26, rotates clockwise, causing idler 102 to drive gear 104,which in turn drives internal ring gear 23 (fixedly secured to winchdrum 22). When the winch drum 22 is pulled through in the forwarddirection, gear 104, idler 102, and medium-speed pinion 34 are rotatedby the drum, but the rotation of pinion 34 is not transmitted to driveshaft 26 or crank 28. The drive shaft is isolated from the pinionbecause the corresponding drive carns operate only in a forwarddirection and slip when the direction of relative shaft rotation isreversed (see FIG. 6). This isolation feature applies similarly to boththe high and low-speed pinions 32 and 36. Forward rotation of either ofthese two pinions is also isolated from the drive shafi and crank.(There is a further, later to be described, isolation between the winchdrum and the lowspeed drive linkage.)

Pawl mechanism 110 prevents the winch drum 22 from rotating in a reverse(counter-clockwise) direction. The details of pawl mechanism 110 areshown in FIG. 5. lntemal ratchet 113 is fixedly secured to base 24. Paw]support 111 is coaxial with and secured to the underside of gear 104.Pawls 112 are spring-loaded by spring elements 112a to engage internalratchet 113, thereby permitting only forward (clockwise) rotation of thewinch drum 22 and preventing reverse rotation. This feature is importantin that when the winch is under load, the crank 28 can be releasedwithout permitting the load to back off and without risk of the crankbeing accelerated by the load and thus endangering the operator.

Low-speed pinion 36, when engaged to shaft 26, rotates clockwise,driving idler 120 which in turn drives one-way gear 122 clockwise.lntemal teeth 123 of one-way gear 122 engage pawls 125 secured to theunderside of pinion 126, causing pinion 126 also to be driven clockwiseand to transmit its forward rotation to internal ring gear 23 and thusto the winch drum 22. When the winch is pulled through in a forwarddirection, the pawls 125 do not engage one-way gear 122, andconsequently the only portion of the low-speed drive linkage that iscaused to rotate is pinion 126; by reducing friction, this makes iteasier to manually haul a line around the winch when no mechanicaladvantage is required.

Further structural features of the winch mechanism are shown in FIG. 4.The base 24 is fixedly secured to gear housing 25 which is in turnfixedly secured to vertical sleeve 27. Gear housing 25 provides aconvenient mounting for the various elements of the medium and low-speeddrive linkages; sleeve 27 supports the drive shaft bearings (e.g. 92 and94) and drum bearings (e.g. 96 and 98).

The winch drum body 93 is preferably made of cast nylon, sheathed by aprotective metal shell 95 at those portions of the drum periphery mostsubject to wear from the lines to be hauled, and lined by a metal sleeve99. Drum body 93 can be cast integrally with ring gear 23 (the outersurface of which is provided with threads 23a to prevent relativemovement between the drum body and ring gear). Preferably, thesethreads, which are of low pitch, are roughened to reduce the chance ofrotational movement of the gear with respect to the drum body and areoriented so that any torque which occurs when the winch is under loadtends to bias the gear 23 into the drum body.

Proper choice of materials can greatly increase the strength anddurability of the winch and can provide a significant reduction inweight for a given hauling capacity. For marine use, satisfactoryresults have been obtained by using a corrosion-resistant type 316stainless steel for base 24, gear housing 25, and sleeve 27, and aharder high-strength type 17-4 RH" steel for drive shaft 26, cam-controlrod 70, and the drive linkages. Yet stronger steels (e.g. type can beemployed where operating requirements so dictate.

The preferred embodiment described above and shown in the figuresprovides a three-speed winch, but obviously the same principles ofconstruction and operation can be applied to other winches with agreater or lesser number of speeds and of widely varying size andhauling capacity. Further obvious modifications permit the winch to beconverted readily to powered operation.

Other embodiments will occur to those skilled in the art and are withinthe following claims.

What is claimed is:

l. A shaft engager for transmitting rotary motion of a drive shaft toany of a plurality of pinions comprising:

a plurality of independently rotatable pinions;

a rotatable drive shaft coaxial with said pinions and extending throughthem;

a plurality of drive cams, each associated with one of said pinions andmounted to said shaft for movement from a first extended positionengaging said associated pinion and preventing relative rotation betweensaid pinion and said shaft in at least one direction to a secondretracted position not engaging said pinion and permitting relativerotation between said pinion and said shaft;

and, means for selecu'vely extending said drive cams to said firstposition and thereby causing said drive shaft to drive selected sets ofsaid pinions, said sets each comprising at least one pinion.

2. The shaft engager of claim 1 wherein said means for selectivelyextending said drive cams comprise a cam-control rod coaxial with saiddrive shaft and movable relative thereto and having cam-control surfacesadapted to be positioned for cooperation with said drive cams.

3. The shaft engager of claim 2 wherein said cam-control rod isrotatable with respect to said drive shaft, the surface of saidcam-control rod comprises sets of cam-control grooves, each such setadapted to be positioned to cooperate with an associated set of drivecams and to control the position assumed by the drive cams comprisingsaid associated setin accordance with whether or not the angularorientation of said cam-control rod is selected to bring said set ofgrooves into angular registration with said set of cams, each set ofgrooves comprising at least one groove and each set of cams comprisingat least one cam.

l i i I

1. A shaft engager for transmitting rotary motion of a drive shaft toany of a plurality of pinions comprising: a plurality of independentlyrotatable pinions; a rotatable drive shaft coaxial with said pinions andextending through them; a plurality of drive cams, each associated withone of said pinions and mounted to said shaft for movement from a firstextended position engaging said associated pinion and preventingrelative rotation between said pinion and said shaft in at least onedirection to a second retracted position not engaging said pinion andpermitting relative rotation between said pinion and said shaft; and,means for selectively extending said drive cams to said first positionand thereby causing said drive shaft to drive selected sets of saidpinions, said sets each comprising at least one pinion.
 2. The shaftengager of claim 1 wherein said means for selectively extending saiddrive cams comprise a cam-control rod coaxial with said drive shaft andmovable relative thereto and having cam-control surfaces adapted to bepositioned for cooperation with said drive cams.
 3. The shaft engager ofclaim 2 wherein said cam-control rod is rotatable with respect to saiddrive shaft, the surface of said cam-control rod comprises sets ofcam-control grooves, each such set adapted to be positioned to cooperatewith an associated set of drive cams and to control the position assumedby the drive cams comprising said associated set in accordance withwhether or not the angular orientation of said cam-control rod isselected to bring said set of grooves into angular registration withsaid set of cams, each set of grooves comprising at least one Groove andeach set of cams comprising at least one cam.